LONDON (AP) – One month after Jose Mourinho said Luke Shaw could be Manchester United's best left back, the England international could be looking for a new club.

Mourinho questioned the defender's commitment after again leaving Shaw out of his squad for the 0-0 draw against West Bromwich Albion on Saturday.

''It's difficult for him to be on the bench,'' the United manager said of the 21-year-old Shaw, who is behind Matteo Darmian, Daley Blind and Marcos Rojo for the left back position. ''I cannot compare the way he trains and commits, the focus, the ambition. He is a long way behind.''

When Shaw joined United from Southampton in 2014 for reportedly for more than 27 million pounds ($46 million), Shaw became the world's most expensive teenager.

But his United career has been inconsistent, not helped by being sidelined for nearly a year while recovering from breaking his right leg in a Champions League game against PSV Eindhoven in September 2015.

Shaw has made only two United appearances in the last four months–despite overcoming niggles related to a long lay-off and being fit since mid-January. He has been publicly criticized by Mourinho on several occasions.

In September, the Portuguese coach blamed his player for a mistake that led to a Watford goal. And in November, Mourinho questioned Shaw's commitment, saying ''to compete you have to go to the limits.''

Shaw made a substitute appearance for England against Germany in a friendly on March 22 but has not played for United since the draw with Bournemouth 18 days earlier.

United is in fifth place in the Premier League, five points behind fourth-place Manchester City in the final Champions League qualification spot.

Everton visits Old Trafford on Tuesday with United having top scorer Zlatan Ibrahimovic and midfielder Ander Herrara available again after suspension.

Record signing Paul Pogba, who has been absent for the last two games because of a hamstring injury, could be fit to return, but Juan Mata and defenders Phil Jones and Chris Smalling remain sidelined.

''I go with mathematics,'' Mourinho said. ''Until it's mathematically impossible, we keep trying and, because this week is a week without the Europa League, we have nothing to think about Europe so this week is easy from the focus point of view.''